Building Materials & Insulation
Installing a renewable energy technology to heat your home could be a waste of time unless you prevent the heat from escaping. For a building to be healthy, it should also be able to breath. This means that chemicals used inside the house should be able to escape and that the air within the house regularly gets changed. There are several ways of ensuring this.
To prevent heat from escaping, you should consider the quality and nature of the
insulation in your home. If your home is colder than it
should be, the chances are it requires insulation. The following
(taken from TG4 “Teach Glas” programme) are some things worth
knowing about insulation;
More natural insulation materials such as sheep-wool, hemp and cellulose-fibre generally consume less energy in their manufacture. Typically, walls can account for a third of heat loss: difficult to cure on existing houses, but various materials can be blown into the wall cavity through coin-sized holes.
Close curtains at night and do not let curtains hang over the radiators. Curtains with thermal lining that are tight to the wall are preferable.
There is more than an even chance your attic is not properly insulated, and what you have may be flattened (and less effective over time); it can cost less than a tank-load of oil to do the job and save a third of all heat loss.
If using fibreglass, use a minimum of 250mm (100mm between joists & 150mm across joists).
Polyurethane insulation is not permitted on the inside of buildings in some European countries as it is claimed it results in off-gassing which contributes to what is known as "sick house syndrome".
U-Value indicates the rate of heat loss through any given material or combinations of materials (e.g. wall, roof); the lower the U-value the better.
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Sometimes R-values are given - the higher the R-value the better.
Cellulose fibre insulation is recycled paper that is treated to resist fire and fungus attack.
Rock Wool is stone, heated at 1600ºC and turned into fibre - a bit like candyfloss.
Fitting reflective foil (ideally with some insulation) on the external walls behind radiators will significantly reduce heat loss through such walls.
Leaving an attic without insulation leaves little between you and the cold outside. An uninsulated roof has a U-Value of 2.3 which is equivalent to leaving two 60w bulbs running 24 hours a day!! (2.3 x 50m sq = 115w). With basic insulation this comes down to around 20w (0.4 x 50 m sq) almost 1/6th.
The
table below shows standards to look for when buying insulation:
The
Energy Label is a method by which we can all compare the energy
efficiency of our homes, as we would the fuel consumption of a car.
It helps compare like with like and comes about as a result of a test
by an approved energy assessor who must also provide a list of
recommendations that can bring about improved energy usage, which
results in lower fuel bills and greater comfort. In cars we refer to
miles/gallon or litres/km; in our homes it is kWh/m2/year (Kilowatt
Hours per metre square per year).
The BER (Building
Energy Rating) system currently applies to the sale or rental of all
new homes for which planning permission is applied for from January
2007 onwards. From January 2009
all homes put up for sale or rent will be required by law to provide
an energy rating certificate.
The label will be
valid for up to 10 years. You can expect to pay upward of €300 for
an energy assessment for an average home. Energy assessors can be
found in the Golden Pages. As it is very likely to affect the resale/
letting value of properties in future, it is an advantage to conduct
an assessment at an early stage so that recommended improvements can
be undertaken and the benefits gained that bit sooner.
On different budgets from €80 to €10,000 you could make the following energy savings:
You could replace all your normal light bulbs with CFL bulbs for around 80 euros, saving 40 euros per year.
You could pump insulation into your house's cavity walls for about €600, saving €150 per year.
You can increase the amount of insulation in your attic to 300 mm for around €400, saving €75 euros per year.
Spending €1,000 plus labour would provide 300mm of insulation under wooden floors, thus saving €200 per year.
Spending €10,000 he could replace his windows with double glazing, saving about €150 per year.
The following are things that you should look out for when buying a house:
Homes should be designed so that the main living areas, larger windows and conservatories, always face south towards the sun.
Greater heat efficiency is gained from a compact/ standard rectangular design - as less wall area requires less heat.
Sheltered houses are easier to keep warm - the cooling effect of the wind around a house is often underestimated. Deciduous trees provide little wind protection in winter. But when south-facing they can provide shade during summer and allow welcome sunlight and heat in winter.
If the site slopes, it should preferably slope southward.
Check if the floors /walls between other apartments/houses are sound proof.
If the joists in the attic are not covered by insulation, the chances are that it may be insufficiently insulated. Check that there are no draughts - anywhere!
Homes requiring the use of electric heating systems are to be avoided. Is the heating system based on a renewable source?
Thermostatic valves on radiators, a factory insulated water heating tank and CFL bulbs indicate that energy efficiency has been taken into account to a basic degree at least.
The Energy Ratings were conducted in accordance with the Dwelling Energy Assessment Procedure, or DEAP, published by Sustainable Energy Ireland. This is the official methodology to be used for the rating of all new homes, meeting the requirements of the European Energy Performance in Buildings Directive. For more information on this subject check out www.sei.ie/epbd